1. Field of the Invention
The present invention relates to a rotary push switch device that is preferably applied to an input to an air conditioner, a navigator, and the like, which are mounted on a vehicle, and is most suitable when a design is formed at a center.
2. Description of the Related Art
There are many switch devices that employ known technologies and can be subjected to rotary and push operations. For example, various types of electric parts such as rotary switches, push button switches, and the like, which are used in audio systems, air conditioners, and the like, are mounted on vehicles, and these electric parts are operated by drivers and passengers who manually manipulate operation knobs. Among these vehicle-mounted electric parts, there is known a rotary push switch device used in, for example, an audio system. The rotary push switch device has a rotary switch, which adjusts a sound volume of the audio system, and a push button switch, which is disposed in the rotary switch and turns on and off a power supply to the audio system as well as has a rotary knob for operating the rotary switch and a push knob for operating the push button switch, and these knobs are disposed coaxially with each other. Further, there is also known a rotary push switch device applied to a digital camera with a zoom function as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2001-357758 (refer to paragraph Nos. 0011 to 0029 and FIGS. 2 and 3 of the specification), which will be shown in FIGS. 4 and 5.
The rotary push switch device shown in FIGS. 4 and 5 is a device applied to a digital camera with a zoom function. The switch device is mainly composed of a support plate 1 made of a metal plate and the like, a flexible substrate 2, which is made of an insulating base member such as a polyester film and the like and has electric conductive patterns formed thereon, a first dome-shaped click spring 3 that also acts as a first movable contact element, a synthetic resin guide member 4 having a plurality of guide projections 4a, a synthetic resin drive member 5, which has a push projection 5a and can be caused to rise and fall by being guided by the guide projections 4a, a second dome-shaped click spring 6 that also acts as a second movable contact element, a metal slider element 7, a synthetic resin slider element receiver 8 to which the slider element 7 is attached, a synthetic resin accommodation member 9 having a ceiling portion 10 and a cylindrical portion 11, a self-return torsion spring 12, a synthetic resin key top 13, and a synthetic resin rotary operation member 14 arranged integrally with the slider element receiver 8.
The flexible substrate 2 is assembled in the rotary push switch device with its band-shaped portion 2c bent in an S-shape.
The first dome-shaped click spring 3, which also acts as the first movable contact element, is formed of a stainless steel sheet spring and formed in a dome shape. The click spring 3 is placed on the region of the flexible substrate 2, in which a first stationary contact element (not shown) is formed, comes into contact with an outer ring-shaped portion of the stationary contact element at all times as well as confronts an inner disc-shaped portion of the stationary contact element so as to come into contact with and depart from the portion. A first push switch element S1 is composed of the first click spring 3 and the first stationary contact element. When a somewhat large press operation force is applied to the click spring 3, the inverted central portion of the click spring 3 is caused to come into contact with the disc-shaped portion of the stationary contact element that confronts the central portion, so that the inner stationary contact element is electrically connected to the outer stationary contact element.
Since the second dome-shaped click spring 6, which also acts as the second movable contact element, is made of a stainless steel spring sheet and formed in a dome shape, the central portion of the click spring 6 can be inverted by a press operation force smaller than that of the first click spring 3. The second click spring 6 is placed on the region of a band-shaped portion 2c of the flexible substrate 2, in which a second stationary contact element (not shown) is formed, comes into contact with an outer ring-shaped portion of the stationary contact element at all times and confronts an inner disc-shaped portion of the stationary contact element so as to come into contact with and depart from the portion. A second push switch element S2 is composed of the second click spring 6 and the second stationary contact element. When a relatively small press operation force is applied to the click spring 6, the inverted central portion of the click spring 6 is caused to come into contact with the inner disc-shaped portion of the stationary contact element confronting it, so that the inner stationary contact element is electrically connected to the outer stationary contact element.
The guide member 4 has four elastically deformable columnar guide projections 4a, a frame-shaped portion 4b for coupling the base ends of the respective guide projections 4a, and three attachment projections 4c which extend from the frame-shaped portion 4b in a direction opposite to the guide projections 4a. Each guide projection 4a has a claw portion 4d projecting inward at the extreme end (free end) thereof. Further, the frame-shaped portion 4b has an engagement groove 4e that is formed thereto by projecting a part of the frame-shaped portion 4b outward in an L-shape.
The drive member 5 includes a push projection 5a for pushing the first click spring 3, a flat sheet portion 5b projecting the push projection 5a from the center thereof, engagement cutouts 5c, which are formed at four positions on the outer peripheral portion of the flat sheet portion 5b and into which the guide projections 4a are loosely inserted, respectively, an L-shaped hook 5d projecting sideward from flat sheet portion 5b, and a small projection 5e projecting from the flat sheet portion 5b sideward on a side opposite to the hook 5d. 
The accommodation member 9 includes the ceiling portion 10, which has an opening 10a at the center thereof and arc-shaped slots 10b disposed at four positions, a cylindrical portion 11 suspending downward from the outer peripheral portion of the ceiling portion 10, and attachment projections 11a projecting at equal intervals from the bottom surface of the cylindrical portion 11 at six positions. Further, a ring-shaped wall 10d, which regulates the position of the self return torsion spring 12 from an inside, and a spring receiving portion 10f, which causes a taper surface 10e to collide against an end of the torsion spring 12 and to stop thereat, stand on the ceiling portion 10, and the torsion spring 12 is assembled between the ring-shaped wall 10d and the spring receiving portion 10f. 
The drive member 5, on which the second push switch element S2 is placed, and the guide projections 4a of the guide member 4 are disposed in the opening 10a of the accommodation member 9. Further, the slider element receiver 8 is disposed inwardly of the cylindrical portion 11 of the accommodation member 9 in confrontation with the ceiling portion 10, and the outer peripheral surface of the slider element receiver 8 is in sliding contact with the inner peripheral surface of the cylindrical portion 11. Then, the rotary operation member 14 is integrated with the slider element receiver 8 by inserting four coupling projections 14b of the rotary operation member 14, which is disposed on the ceiling portion 10 of the accommodation member 9, into the slots 10b, respectively and further into coupling holes 8b of the slider element receiver 8, and thermally caulking the extreme ends of the respective coupling projections 14b to the bottom surface of the slider element receiver 8. Accordingly, the rotational motion of the rotary operation member 14 is guided by the inner peripheral surface of the cylindrical portion 11 that functions as a bearing surface with respect to the outer peripheral surface of the slider element receiver 8.
The rotary operation member 14 has an opening 14a, in which the key top 13 is disposed, at the center thereof. The coupling projections 14b project from the bottom surface of the rotary operation member 14 at four positions at equal intervals, and the rotary operation member 14 is integrated with the slider element receiver 8 through the coupling projections 14b. Note that a push projection 13a, which projects from the center of the inner bottom surface of the key top 13, is mounted on the second click spring 6 in a state that the rotation of the key top 13 is prevented by the rotary operation member 14, and the rising and falling motion of the key top 13 is guided by the inner wall portion of the rotary actuating member 14.
An operation of the rotary push switch device arranged as described above will be explained. First, an operation of a push switch portion, which is pressed through the key top 13, will be explained. Next, an operation of a rotary type electric part portion, which is rotated through the rotary operation member 14, will be explained.
When an operator pushes the key top 13 with a finger in a predetermined amount, the push projection 13a of the key top 13 inverts the second click spring 6 having a small operation force, thereby the second push switch element S2 is switched from an on-state to an off-state. When the operator further pushes the key top 13, the drive member 5 is caused to fall while the on-state of the second push switch element S2 is kept, thereby the push projection 5a of the drive member 5 inverts the first click spring 3 having a large operation force, so that the first push switch element S1 is switched from an off-state to an on-state. Accordingly, when a click feel is imparted at the time the operator lightly pushes the key top 13, the operator can feel that the second push switch element S2 has been turned on, and when a click feel is imparted at the time the operator strongly pushes the key top 13, the operator can feel that the first push switch element S1 has been turned on. Specifically, in the embodiment, when the second push switch element S2 is turned on, a digital camera is focused, and when the first push switch element S1 is turned on, a shutter is actuated.
Further, when the rotary operation member 14 is rotated by the operator, the slider 7 is rotated together with it and slides on the sliding patterns (a resistor pattern and a collector pattern) formed on the flexible substrate 2, thereby a resistance value is output according to a position of the rotatingly moved slider 7. That is, a different resistance value can be output according to an amount of rotation of the rotary operation member 14, and in this embodiment, zooming of the digital camera can be executed by rotating the rotary operation member 14.
Incidentally, in a known rotary push switch device, a center knob on which a center logo is formed, is arranged so as not to be rotated. Accordingly, since a knob (key top 13) located at a center has only a push function and a rotary function is provided with only an outside knob (rotary operation member 14), when a push operation is executed continuously from a rotary operation, it is difficult to execute the push operation by means of the outside knob, and thus the known rotary push switch device is disadvantageous in operability.
Accordingly, an object of the present invention, which was made in view of the above circumstances of the related art, is to provide a rotary push switch device arranged such that when a push operation is executed through a push knob, the push operation is executed by a rotary push knob in association with the push operation of the push knob.